Pressure switch



Dec. 30, 1952 H. H. WOLFE ET AL 2,623,963

PRESSURE SWITCH Filed April 27, 1948 3 Sheets-Sheet l l I l 10fP/Nvswoes H. H/X MJLFE EDWARD w. HAAS VJ."- ,5 9mm,- ATTORNEYS Dec. 30,1952 H H. WOLFE ETAL PRESSURE SWITCH 3 Sheets-Sheet 2 Filed April 27,1948 5.. 5 Y 5 A REA 0W5 mm mm. i AA/AaA ANA-AKI m w m I i WM 2 h /...m.1 mm m. m \w n ll v M uv 3 Q Mnh I 9 9n on an fl m j 3 w mu A: mAQAA/ AQm a e 6... 3 V 7 V 3 i mm 7 7 mm be 1 av d Q Ma 3 T E 3, 3 3 n 8 8 K +9"a w v n a w UP 2 a m mw an 3 Dec. 30, 1952 H. H. WOLFE ETAL PRESSURESWITCH 3 Sheets-Sheet 5 Filed April 27, 1948 EDWARD W. HIMS INVENTOESH.HIX WOLFE ATTORNEYS Patented Dec. 30, 1952 PRESSURE SWITCH H. HixWolfe and Edward W. Haas, Dayton, Ohio,

assignors to The Dayton Pump & Manufacturing Company, Dayton, Ohio, acorporation of Ohio Application April 2'7, 1948, Serial No. 23,536

2 Claims. 1

This invention relates to pressure switches and to improvements therein,and is particularly concerned with the types of pressure switches whichare used on water pumping systems and the like.

The usual type pressure switch for use with water systems, such asdomestic systems, is quite complex and is often difficult to adjust andrepair due to a plurality of small parts and to the arrangement of theseparts in the switch. It is desirable, and particularly with switches fordomestic installation, to simplify the structure of such a switch toreduce the chance that it will become inoperative and render the systemit controls useless for a long period of time.

Furthermore, such pressure switches generally have rollers and cams andsimilar mechanisms which have an inherent amount of friction thatmaterially detracts from the accuracy with which the switch can beadjusted to open or close at any predetermined pressure.

The primary object of the present invention is to provide an improvedpressure switch of the type referred to above and which overcomes theobjectionable features of the ordinary type pressure switch.

It is another object of this invention to provide an improved pressureswitch constructed of a relatively few number of parts and beingsubstantially free of frictional engagement of the moving parts witheach other.

A still further object is the provision of an improved contactarrangement for a pressure operated switch simple to construct and whichcan readily be assembled and disassembled from the switch.

These and other objects and advantages will become more apparent uponreference to the following description taken in connection with theaccompanying drawings in which:

Figure 1 is a vertical section taken through the switch of thisinvention and showing it with the contacts in open position;

Figure 2 is a view similar to Figure l but showing the contacts of theswitch in closed position;

Figure 3 is a View similar to Figure 2 but with the contact portion ofthe switch removed in order better to show the pressure responsiveactuator for the switch;

Figure 4 is a plan view looking down on the w actuator mechanism shownin Figure 3;

Figure 5 is a plan view looking down on the switch and terminal block;

Figure 6 is a vertical section indicated by the line 6--6 on Figure 5;

Figure 'I is a view similar to Figure 6 and in dicated by the line 1'lon Figure 5:

Figure 8 is a section view indicated by the line 8-8 on Figure 1;

Figure 9 is a perspective view of the actuator mechanism; and

Figure 10 is a perspective view showing the member which transmitsthrust from the pressure diaphragm to the actuator mechanism.

Referring to the drawings, the switch according to this inventiongenerally comprises a part indicated at H), which is the pressureresponsive portion of the assembly, a part indicated at l2, which is theactuator portion of the assembly,

and a portion indicated at H. which is the terminal block and contactassembly.

These several parts are assembled together and are then enclosed with acasing l6 which includes the removable cover 18. The entire assembly isthen ready to be connected to the electric lines to be controlled by theswitch and the pressure part I!) and can be connected with the source ofpressure which is to eiiect the said control.

Referring to the aforementioned pressure part Hi, this will be seentocomprise a bottom or base part 20 having a threaded opening 22 thatreceives a pressure pipe, as, for example, the pressure line leadingfrom a pump to the reservoir.

The upper portion of the cast part 20 has a machined peripheral flangeand against this flange there is the flexible diaphragm 24. Thediaphragm 24 is retained in position by the screws 26 which extendthrough the member 29 and the periphery of the flange and intoengagement with a plate 28.

The lower portion of the casing 16 is turned in as indicated at 30 andis clamped between the periphery of the plate and the marginal portionof the diaphragm 24. Resting on top of the diaphragm 24 is an actuatorplate 32 which has arms 34 extending upwardly from each side thereof andextending through the openings 35 in the plate 28. The member 32 and thearms 34 are for the purpose of transmitting thrust from the diaphragm 24to the switch actuator mechanism at l2.

Referring to the actuating mechanism, this will be seen to comprise abracket member 38 mounted on the plate 28 by the rivets 39 and havingthe spaced upstanding arms Ail at one end and the more widely spacedupstanding arms 42 at the other end.

The said arms are notched on their inside edges as indicated at M and apair of bifurcated or U-shaped plates are arranged to have their legsengaged by the said notches. As shown, a first plate 4% is arranged sothat the ends of its legs 33 are engaged by the notches M in theupstanding arms 40. Similarly, a second plate 56 is arranged to have theends of its legs 52 engaged by the notches in the upstanding arms 42.

It will be noted that the plate 59 is substantially larger than theplate 66 and extending completely around the upstanding arms 40, andthat each of the legs 52 thereof have the V-shaped recesses therein andwhich are positioned to be engaged by the V-shaped upper ends of thearms 3d upstanding from the plate 32.

Having its head positioned beneath the plate 23 and extending upwardlythrough an aperture 56 in the closed end of the plate 59 is a bolt 58. Aspring fill surrounds the bolt and bears at its lower end on the top ofthe plate 50 and at its Turning now to the contact and terminal block IM of the switch, this will be seen in Figures 1, 2 and 5 through 8 tocomprise a block ill of insulating material and which has extendingtherein from one side a pair of recesses .12. The recesses 12 aresubstantially rectangular and extending into each end of each of therecesses is a stationary contact plate it. Each of the contact plates 74is connected with a rod 16 which extends transversely through the blockit to the side 78. The screw i8 is for the purpose of connecting theelectric leads 8% to the said rods, and as will be noted in Figure 5 theleads are brought into the ends of the rods through grooves or slots 82in the adjacent side of the block ll).

Disposed in each of the recesses 12 between the bottom thereof and thestationary contact plate M are the movable contact plates 8d. Theseplates are adapted for bridging the stationary contact plates when intheir Figure 2 position and for interrupting the electrical connectionbetween the plates when in their Figure 1 position.

The movable contact plates are guided and actuated by the blades 85 ofinsulating material which extend through the plates 84 and intotherecesses 88 of the block it. A spring 9!! surrounds each of the blades8d and continuously urges the associated movable contact plate towardits contact making position.

Each of the blades 55$ is shouldered as at 92 and thus when movedupwardly engages the associated movable contact plate and lifts it fromits contact making position. The blades 85 extend beyond the limits ofthe block ii and there is a cover plate 9 which closes the recess 12 andalso retains the blades 85 in position.

The block 78 together with its contacts, contact actuating blades, andcover plate at, is mounted in position on the actuator I2 by means ofthe screws 95 which extend through the said block and cover plate andinto the turned back tabs 98 and I05) which are integral with thebracket 38.

In Figures 5, 6 and 7 it will be noted that there is an adjustable screwI02 extending outwardly from the block H; on the actuator side thereof.

This screw is adjustable by means of a socket head therein from the topof the block and serves as a stop for limiting the maximum upwardmovement of the plate 66, as will be seen in Figure 1 wherein the plateand screw are shown in engagement.

The screw also serves to adjust the pressure diiierential within whichthe switch operates, because the closer the screw stops the plate "55 toa horizontal position the smaller the drop in pressure required beneaththe diaphragm 24' to allow the said plate to return to its Figure 2position.

In operation, the switch can be assumed nor mally to have all of itsparts shown in the Figure 2 position. At that time the pressure at whichthe switch will operate is set by means of the nut 55. Thereafter theswitch will remain in its Figure 2 position until pressure builds upbeneath the diaphragm 24 and moves the plate 32 upwardly and the arms 35cause the plate 58 to rotate clockwise about its pivotal connection withthe upstanding arms 42.

The setting of the spring 60 determines the amount of pressure requiredto so move the plate 50. When the plate '50 is moved upwardly until theline of action of the spring 66 is above the engagement of the legs 48of the plate 46 of the upstanding arms 44, the said plate 46 will snapupwardly to its Figure 1 position and bring about a quick opening of theswitch contacts. Thereafter the switch will remain open until thepressure beneath the diaphragm drops to the point where the plate 50will move downwardly and again snap the plate 46 downwardly.

As mentioned before, the pressure at which the switch will open can beadjusted by the nut 64 and the pressure differential, that is, theamount which the pressure must drop beneath the diaopposite the recessestherein and receives a screw phragm 24 before the switch again closes,can

be adjusted by the screw I02. Both the nut and screw are available fromthe top of the switch merely by removing the cover member l8.

It will be apparent that the switch has substantially no friction due tothe pivotal arrangement of the plates 46 and 50 and thus can be adjustedas to operating pressure very accurately. Furthermore, a minimum ofassembling operations are necessary because the switch part I 4 ismerely assembled and then is retained in assembled position by the samemeans which secures it in place on the bracket of the actuator.Similarly, in the actuator the two plates 46 and 50 are retained inposition by the same spring which causes the plate 46 to snap overcenter.

It will be apparent that the construction of the switch is inexpensiveand that the assembly thereof is quite simple, and servicing and repairof the switch can easily be done at any time.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

We claim:

1. In a pressure switch including a switch casing cover; a terminalblock unit of insulating material demountable from the switch mechanismupon removal of switch casing cover, a plurality of bores extending fromone side to the other of said block, recesses in said one side adjacentsaid bores, notches in the said one side connecting said recess with apair of said bores, contact means comprising rods extending through said5 bores and plates fastened to said rods and extending along saidnotches to overlie said recesses, and a cover plate of insulatingmaterial on said one side closing said recesses and thereby enclosingsaid contact means in position.

2. In a pressure switch including a switch casing cover; a terminalblock unit of insulating material demountable from the switch mechanismupon removal of switch casing cover, a plurality of bores extending fromone side to the other of said block, recesses in said one side adjacentsaid bores, notches in the said one side connecting said recess with apair of said bores, contact means comprising rods extending through saidbores and plates fastened to said rods and extending along said notchesto overlie said recesses, a cover plate of insulating material on saidone side closing said recesses and thereby enclosing said contact meansin position, blades extending through said cover plate and recesses intosaid block and having shoulders thereon adapted for contact with theinside of said cover plate, and movable contact means in said recessesspring urged toward the fixed contacts and adapted for engagement withthe shoulders on said blades whereby actuation of said blades willseparate the movable and fixed contacts.

H. HIX WOLFE.

EDW. W. HAAS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

